In recent years, along with advancement of portable appliances and the like, demands are increasing for a highly stable and highly precise piezoelectric device that is used in such appliances. As a configuration for achieving the highly stable and highly precise piezoelectric device, a combination of a piezoelectric vibrator and a circuit element is now coming into use.
By way of example, the patent document 1 discloses a piezoelectric device which is highly stable and highly precise. FIG. 9 illustrates a structure of such conventional piezoelectric device.
In FIG. 9, an external connecting terminal 101 and an input-output terminal 102 are mounted on the underside 107 of a package 103 of the piezoelectric device 100. The external connecting terminal 101 and the input-output terminal 102 are terminals for inputting control data into a circuit element (not illustrated), for achieving highly stable and highly precise characteristics of the piezoelectric device 100. Electrical signals of the control data are inputted into the circuit element (not illustrated) via the external connecting terminal 101 and the input-output terminal 102.
The piezoelectric device 100 operates based on the control data being inputted. The external connecting terminal 101 and the input-output terminal 102 output externally, characteristic data that is obtained according to the operation of the piezoelectric device 100. The characteristic data externally outputted can be utilized for a characteristic inspection of the piezoelectric device 100.
The input-output terminal 102 is a terminal provided specifically for inputting of the control data into the circuit element provided in the piezoelectric device 100, or outputting the characteristic data of the piezoelectric device 100. On the other hand, the external connecting terminal 101 is a terminal that is used when the piezoelectric device 100 is in driving operation. The external connecting terminal 101 is a terminal to be electrically connected with an external circuit board (not illustrated) when the piezoelectric device 100 is mounted on the external circuit board (not illustrated). The external connecting terminal 101 is used to input the control data and output the characteristic data, as performed for the piezoelectric device 100, and in addition, it is also used for supplying electric power into the piezoelectric device 100, and performing oscillation output.
After executing the input of control data into the circuit element of the piezoelectric device 100, the characteristic inspection of the piezoelectric device 100, and the like, the external connection terminal 101 is used as a power voltage supplying terminal for supplying power voltage into the piezoelectric device and as an oscillation output terminal for taking out the oscillation output from the piezoelectric device. On the other hand, the input-output terminal 102 is a dedicated terminal for inputting the control data or outputting the characteristic data, and it becomes unnecessary after the installation on the external circuit board.
The surface of the external connecting terminal 101 and the surface of the input-output terminal 102 of the piezoelectric device 100 are gold-plated, which is solder wettable, in general.    [Patent Document 1]    Japanese Unexamined Patent Application Publication No. 2001-102869